I have an 08 e93 M3 with nav. I understand that they made a ton of upgrades after 08. But really interested in the f nav. Can I use the same screen just upgrade the computer and controller? Is it worth it I would love to integrate my iPhone more into the car? And if so do you know where I can get one? Or should I just go with a 09 or newer?

You cannot use the same display; the new CIC iDrive uses a much higher-resolution display, and if you were to try to view it on the lower-resolution CCC display (if it even worked) you probably wouldn't be able to read anything. You CAN retrofit the new iDrive controller to your system and all of the dedicated buttons will work, no software mods or anything required. Obviously it won't get you the new interface and display, but you'll get those shortcut keys. Otherwise yeah you're looking at a fairly extensive (and expensive) retrofit.